1. Field of the Invention
The present invention relates to a fan unit assembled as a single unit, a fan assembly having a fan case for housing the fan unit, and a product comprising this fan assembly.
2. Description of the Related Art
Fans are installed in a wide range of industrial and consumer products for moving air heated by heat sources inside the product to the outside of the product. More and more industrial products operate continuously all the day, and the ability to maintain and replace parts without turning the power off and with the product continuing to operate is desirable. Fans are no exception, and fans which can be replaced while the power supply to the product in which the fan is used remains on are needed. Continuous operation also shortens fan service life, thus increasing the opportunities for fan replacement. It is therefore also necessary to improve the safety and ease with which fans can be replaced.
FIGS. 37 to 39 show a typical fan unit, FIGS. 37 and 38 being perspective views thereof from different directions, and FIG. 39 being an exploded perspective view of the fan unit.
As shown in these figures, the fan unit 900 comprises a fan 910, fan box 920, printed circuit board 930, LED 940, and a plurality of screws 950.
The fan 910 has a frame 911 and a fan blade 912 freely rotatable to the frame 911. A mounting hole 913 is disposed at each of the four corners of the frame 911.
The fan box 920 is typically formed by shaping sheet metal. A finger guard 921 preventing a finger from entering the fan is formed at the ventilation opening in the bottom or side as seen in FIG. 38. A cantilevered beam-shaped operating lever 922 is further disposed to the fan box 920. When the fan unit 900 is housed in a fan case (not shown in the figures), this operating lever 922 prevents unintentional removal of the fan unit 900 from the fan case. It can also be operated so that the fan unit 900 can be removed from the fan case.
A control circuit (not shown in the figures) for controlling rotation of the fan blade 912, and switching the LED 940 on/off, is provided on the printed circuit board 930. Also provided thereon are a connector 931 for connection with the LED 940, and a connector 932 for connection with the fan 910 motor (not shown in the figures). These connectors 931, 932 are connected with the LED 940 and fan 910 (that is, the fan motor) by wiring not shown in the figures. As also shown in FIG. 37, a guard edge 933 protruding to the front of the fan unit when the fan unit 900 is assembled is also formed on this printed circuit board 930. This guard edge 933 is inserted to a connector (not shown in the,figures) coupled to the printed circuit board 930, and transfers power and signals therefrom to the printed circuit board 930.
A plurality of screws 950 of a plurality of types are used to assemble this fan unit 900.
As shown in FIGS. 37 to 39, a conventional fan unit thus comprised has a plurality of fan boxes 920 made from sheet metal, and is assembled using a large number of screws. Assembly is thus inefficient and costly.
The productivity of the process for housing this fan unit 900 into a fan case (not shown in the figures) and connecting a connector to the guard edge 933 of the printed circuit board 930 [920, sic] is also poor. There are also maintenance-related problems.
With respect to the aforementioned problems, it is therefore an object of the present invention to provide a fan unit that is easy to handle and reduces cost. A further object is to provide a fan assembly whereby fan unit maintenance and replacement are simple. Another object is to provide an apparatus (product) comprising a fan assembly of the present invention.
To achieve this object a fan unit according to the present invention comprises a fan, a fan housing frame, and a fan housing cover. The fan has a frame, a fan blade freely rotatable to the frame, and an installation member disposed to the frame. The fan housing frame has an opening on one side for disposing the fan internally thereto, a ventilation opening in the opposite side, and an engaging member formed on an inside wall for engaging the installation member of the internally disposed fan and thereby determining the fan position. The fan housing cover has a ventilation opening, and an engaging member on an inside wall for engaging the installation member of the fan internally disposed to the fan housing frame. The fan housing cover thus engages the fan housing frame so as to cover the opening into which the fan is installed, and in conjunction with the fan housing frame secures the fan in the fan housing frame.
With a fan unit of the present invention, a fan placed into the fan housing is positioned therein by inserting engaging protrusions (tabs and claws) of the fan housing frame and cover into corresponding holes. No screws are therefore needed to secure the fan in the fan housing. The fan housing cover is similarly engaged with the fan housing frame by means of matching tabs, claws, and holes, and no screws are therefore needed to secure the cover to the box frame.
A fan unit according to the present invention can thus be easily assembled without using any screws or tools such as screwdrivers, and thus helps reduce manufacturing cost.
The present fan unit further preferably has a finger guard formed to the opening of the fan housing frame from which the fan is not inserted (the bottom opening below); and a finger guard formed to the opening in the fan housing cover.
As shown in FIG. 37 to FIG. 39, a fan unit according to the related art only has a finger guard on one side. This makes maintaining or replacing a fan while turning at high speed in the product in which it is used potentially dangerous. Safety can be improved, however, by providing a finger guard on both sides of the fan unit as per the present invention.
Yet further preferably, the fan housing frame and fan housing cover of a fan unit of the present invention are resin moldings.
In addition to helping reduce cost, using resin moldings assures that the box frame and cover are electrically isolated from the power source so that safety can be further improved when maintaining or replacing an operating fan.
The finger guard of a fan unit according to the related art as shown in FIGS. 37 to 39 is made from sheet metal. The finger guard thus provides great resistance to air flow, and is the source of quite loud noise.
However, by molding the finger guard from resin, the finger guard can be shaped to produce little air resistance, and is thus effective as a way to reduce noise.
Yet further preferably, the fan unit comprises a printed circuit board having on one end a card edge for insertion to a connector, and having a control circuit mounted thereon for controlling fan blade rotation. The fan housing frame in this case also has an opening for passing the card edge of a printed circuit board disposed internally to the fan housing frame outside the fan housing to the front in a specific insertion direction orthogonal to the direction of air flow of air moved by the fan. The fan housing frame also has a retainer on an internal wall for holding a side of the printed circuit board disposed internally to the fan housing frame. The fan housing cover in this case further has on an internal wall a retainer for holding the printed circuit board side opposite the side held by the fan housing frame. In conjunction with the fan housing frame, the fan housing cover thus secures a printed circuit board disposed internally to said fan housing frame.
Similarly to a fan unit according to the related art as shown in FIG. 37 to FIG. 39, a printed circuit board is preferably assembled into a fan unit of the present invention. In a fan unit of the present invention, however, the printed circuit board is held securely by the retainers provided on the fan housing frame in which the printed circuit board is installed and the fan housing cover. As a result, the fan unit of the present invention can still be easily assembled without using any screws or tools even when a printed circuit board is installed in the fan unit.
Yet further preferably, the fan housing frame also comprises a cantilevered beam-shaped operating lever extending in the direction opposite to the direction in which the fan unit is inserted to a fan case. This insertion direction intersects the direction of air flow of air moved by the fan. The operating lever has an engaging member for preventing removal of the fan unit from the fan case when the fan unit is installed to the fan case for housing the fan unit. This engaging member is formed in the middle of the operating lever between the front and back ends in the insertion direction.
It should be noted that the provision of this operating lever is the same as in the related art, but providing this operating lever also improves handling the fan unit of the present invention.
Yet further preferably, the fan housing frame of a fan unit according to this invention has a side wall extending in the direction of air flow and the insertion direction with two edges extending in the insertion direction, and a guide channel formed in the exterior side of this side wall. The guide channel has a first channel part extending from one side wall edge into the middle toward the other side wall edge, and a second channel part extending from the end of the first channel part to the back in the insertion direction.
By thus forming a guide channel in the fan unit, the fan unit can be easily installed to and removed from a fan case even when space is confined as further described below. This improves fan unit handling, as well as the ease of fan unit maintenance and replacement.
A fan assembly achieving the above object comprises a fan case for housing a fan unit, and a connector to which connection is made by installing the fan unit to the fan case. More specifically, the fan unit housed in the fan case comprises a fan having a frame and a fan blade freely rotatable to the frame; a printed circuit board having on one end a card edge for connecting by insertion to a connector, and having mounted thereon a control circuit for controlling fan blade rotation; and a fan housing for internally housing the fan, the printed circuit board with the card edge thereof projecting externally to the front in a specific insertion direction intersecting a direction of air flow of air moved by said fan, and having a ventilation opening on both walls in the direction of air flow. The connector is removably fixed to the fan case, and is connected with the card edge of the printed circuit board projecting forward in the insertion direction by the action of installing the fan unit to the fan case.
A fan assembly according to the present invention thus comprises a fan case in which a fan unit is installed, and a connector to which the card edge of a printed circuit board in the fan unit is inserted. The connector is removably fixed to the fan case, and the card edge of the printed circuit board is inserted to the connector by the operation for installing the fan unit to the fan case. Connection to the connector can thus be accomplished by simply installing the fan unit to the fan case, and a fan assembly in which the assembled fan unit can be installed, maintained, and replaced with great simplicity is thus achieved.
Further preferably, the connector of this fan assembly has a body with an opening for inserting the card edge of the printed circuit board, first and second arms projecting to both sides from the body, and an engaging protrusion formed on the first arm. In addition, the fan case has an arm engaging hole for holding the second arm of the connector, which is inserted thereto by sliding the connector in the direction in which the second arm extends, and a slot in which the engaging protrusion of the first arm is inserted. This slot has an inwardly protruding engaging protrusion for engaging the engaging protrusion of the first arm when the second arm is inserted into the arm engaging hole.
Thus comprised, the connector can be easily and reliably installed and removed from the fan case without using any screws or other fasteners, or any tools.
Yet further preferably, the fan unit of this fan assembly comprises a cantilevered beam-shaped operating lever extending in a direction opposite to a specific insertion direction, and a specific engaging member formed on the operating lever between the ends of the operating lever. The fan case further comprises a removal prevention member for preventing fan unit removal by interfering with the engaging member of a fan unit housed internally to the fan case, and allowing fan unit removal when the operating lever is operated to release interference with the engaging member.
Unintentional removal of the fan unit from the fan case can thus be prevented while also allowing for easy installation and removal of the fan unit to and from the fan case as necessary.
Yet further preferably, the fan case of the fan assembly holds a plurality of fan units stacked together in the direction of air flow.
When thus comprised, air flow can be maintained even part of the plurality of fan units fails.
Yet further preferably, the fan unit of the fan assembly comprises a guide channel in an exterior part of a side wall, and the fan case comprises on an inside wall thereof a guide protrusion that fits into the guide channel. This side wall of the fan unit extends in the direction of air flow and the insertion direction, and has two edges extending in the insertion direction. The guide channel has a first channel part extending from one side wall edge into the middle toward the other side wall edge, and a second channel part extending in the direction opposite the insertion direction from the end of the first channel part. The fan unit is installed to the fan case by sliding the fan unit along the first channel part and then sliding it along the second channel part with the guide protrusion fit into the guide channel.
A fan unit thus comprised can be easily installed to and removed from the fan case even in confined spaces.
Further alternatively, the fan unit in a fan assembly according to the present invention comprises a guide channel in an exterior part of a side wall, which extends in the direction of air flow and the insertion direction, and has two edges extending in the insertion direction. The guide channel has a first channel part extending from one side wall edge into the middle toward the other side wall edge, and a second channel part extending in the direction opposite the insertion direction from the end of the first channel part. The fan case in this fan assembly houses a plurality of fan units with at least two arranged in the insertion direction, is freely removably inserted in the insertion direction to a specific apparatus, and comprises a first section in the back in the insertion direction for holding a fan unit, and a second section in the front in the insertion direction for holding a fan unit. This second section has on an inside wall thereof a guide protrusion that fits into the guide channel. A fan unit is installed to this first section by sliding it in the insertion direction. A fan unit is installed to the second section by sliding the fan unit along the first channel part and then sliding the fan unit along the second channel part with the guide protrusion fit into the guide channel.
When it is necessary to move air over a wide area using a plurality of fan units arrayed side by side, a plurality of fan units can be arranged side by side in the direction in which they are inserted to the fan case, and the fan case is then inserted in the same insertion direction to the device in which the fan array is used. By using the design of the present invention for fitting a guide protrusion (pin) into a guide channel and then sliding the fan unit into place in the part of the fan case to the front in the insertion direction, the fan unit installed to this front section can be easily installed and removed as needed.
An apparatus (product) according to the present invention incorporates any one of the fan assemblies of the invention as described above.
By thus incorporating one of these fan assemblies, the apparatus (product) of the invention provides for simple fan maintenance and replacement.